How to access var in PHP

I'm using selenium-rc with php. I want to show in my test the value of CLASSNAME. How can i present the var? I tried to do $this['drivers']['CLASSNAME'] but this is 开发者_开发问答not working for me.

(This is from the debug)

Thank you!

Looks like it should be:

$this->drivers[0]->CLASSNAME